The anthropometric characteristics were recorded as described by Stavrou et al. (16 (
link)). Tanita MC-980 (Arlington Heights, IL, USA) was used for body composition assessment. We performed the 6MWT, as described in the ATS guidelines, to assess the functional status of the patients (17 (
link)). The parameters O
2 saturation (SpO
2), heart rate (HR) (Nonin 9590 Onyx Vantage, USA), blood pressure (Mac, Tokyo, Japan), and self-assessed lower limb fatigue and dyspnea (
via Borg Scale CR-10) (18 (
link)) were recorded at predetermined time-points of the 6MWT (16 (
link)). The handgrip strength test was performed using an electronic dynamometer (Camry EH 101, South El Monte, CA, USA) (19 (
link)). Patients were asked to perform as many repetitions as possible at a self-regulated pace (safe and comfortable) from a sitting-to-standing position while the arms were crossed at the shoulders so as not to use them as support to assess lower limb strength (30-s Sit-to-Stand test) (20 (
link)). Blood sampling of 10 mL peripheral venous blood for the determination of reactive oxygen metabolites (d-ROMs test, free radical analytical system, FRAS5, Parma, Italy) was performed 20 min before physical fitness tests (21 (
link)). Pulmonary function tests were performed according to the ATS/ERS guidelines (22 (
link)) in the sitting position using a MasterScreen-CPX pneumotachograph (VIASYS HealthCare, Germany). Prior to physical fitness tests, all patients answered questionnaires to measure the quality and patterns of sleep using the Pittsburgh Sleep Quality Index (PSQI) (23 (
link)), cognitive impairment was assessed using the Montreal Cognitive Assessment (MoCA) (24 (
link)), STOP-Bang for stratification for obstructive sleep apnea risk (25 (
link)), and (iv) work ability index (WAI) to investigate the ability to return to work without restrictions (26 ).
A stationary seated bike (Toorx, Chrono Line, BRX R 300) with bluetooth capabilities was used for the measurements. It was connected to the VR application, the Meta Quest 2 (Facebook Technologies, LCC, Hacker Way, Menlo Park, CA, USA) device headset and controllers, and a computer (27 (
link)). This VR training system is called VRADA (VR exercise App for Dementia and Alzheimer's patients) version 4.1 and has been developed by ORAMA-VR and Biomechanical Solutions Engineering based on interviews with older people with mild cognitive impairment. The application of the VR training system includes cognitive exercises with simple math calculations and requests users to observe and count animals that appear in their VR to enhance cognitive health and motivational techniques to address the issue of low motivation for exercise. The system gives an opportunity for each participant to choose their exercise duration, landscape in which they will cycle (forest, beach, or snowy landscape), motivating words that they want to hear during their performance (“Calmly,” “I can,” “I will do it well,” “Very nice,” or no words) and the music to enjoy while cycling. VR controllers with raycast were used as a selection mechanism that allows the user to select an answer by pointing the ray at the button and pressing the trigger button at the controller. Moreover, participants received feedback during their performance, such as indications about cycling time, distance, and speed, and could self-monitor their performance using screen-provided data. They were requested to cycle at a constant speed of between 15 and 20 km/h
1. Simultaneously, speed and distance were recorded every 45 s. At the end of the cycling procedure, participants were informed their scores in math questions, the distance they covered, and they were asked to answer four more questions assessing if they were tired, if they liked the way they exercised, how many animals they saw, and if they repeated the motivational word. In this study, all participants performed the exercise in the forest.
The HR, SpO
2, and self-assessment of lower limb fatigue and dyspnea were performed before and at the end of each exercise condition (VR, no-VR, SSE-VR, and 6MWT) for each patient.
Stavrou V.T., Vavougios G.D., Kalogiannis P., Tachoulas K., Touloudi E., Astara K., Mysiris D.S., Tsirimona G., Papayianni E., Boutlas S., Hassandra M., Daniil Z., Theodorakis Y, & Gourgoulianis K.I. (2023). Breathlessness and exercise with virtual reality system in long-post-coronavirus disease 2019 patients. Frontiers in Public Health, 11, 1115393.